Trouble with Engines: the Avro Manchester


Avro Manchester 5view


In November 1936, the British Air Ministry issued Specification P13/36, which called for a bomber capable of carry a load greater than 8000 lb and powered by a pair of the new Rolls Royce X-type engines, then under development. A further requirement was that the aircraft must have a dive-bombing capability at angles of up to 30 degrees – a requirement that, oddly enough, was also built into the specifications of new German heavy bombers such as the Heinkel He 177 in the late 1930s. The overall result was that the aircraft had to be structurally strengthened, which in the case of the He 177 led to unacceptable weight penalties. The Air Ministry specification also stipulated that the bomb bay was to be large enough to permit the carriage of two 18-inch torpedoes.

The Manchester heavy bomber proposed by Avro was an outstanding design from the airframe point of view, but the engines selected to power it were a cause for concern from the very beginning. The best engine then available was the Rolls-Royce Merlin, but two of these would not provide sufficient power for an aircraft of the size and weight of the Manchester. In any case, the whole of Merlin production was allocated to RAF Fighter Command’s new monoplane fighters, the Hawker Hurricane and Supermarine Spitfire. Consequently, Avro had little choice but to take a gamble and opt for the Rolls-Royce X-Type, soon to be named the Vulture, which was still in the development stage. The 24-cylinder Vulture was, in fact, a marriage of two Rolls-Royce Peregrine engines, one inverted on top of the other, driving a single crankshaft and served by a complex lubricating system. As an insurance against the failure of the Vulture, Avro produced revised designs for the Manchester to accommodate other engines such as the Napier 24-valve radial then in design, as well as a four-engined version with Merlins.

The first flight of the Manchester was delayed by successive design changes ordered by Rolls-Royce as they revised the Vulture during 1938, but the aircraft finally took to the air on 25 July 1939. Although the engines performed well, the aircraft suffered from poor control and a long take-off, even though no armament was fitted. Changes were made to the second aircraft to rectify the control problems, namely increasing the wingspan and adding a small fin on the rear fuselage. These changes had little effect on control but the take-off run was shortened. With orders for the Manchester standing at 1200 and Rolls-Royce increasingly under pressure to concentrate on Merlin production, work on the fourengined airframe continued and showed that control could be improved by increasing the size of the twin rudders.

In August 1940, the first production aircraft was flown to Boscombe Down for tests. The engines were derated in an effort to improve reliability and the first Manchesters were cleared for service with No. 207 Squadron at Waddington. The squadron’s work-up to operational readiness was severely hampered by the unreliability of the Vulture engines, and a great deal of concern was voiced when the aircraft was used in the dive-bombing role originally called for by the Air Ministry. No. 207 Squadron’s first operational sortie with the Manchester was flown on the night of 24/25 February 1941, when six aircraft were despatched with fifty-one other bombers to attack enemy warships at Brest. There were no losses due to enemy action, but one Manchester crashed in England after its engines caught fire. No losses were sustained two nights later, when No. 207 Squadron’s Manchesters formed part of a 126-strong bomber force that attacked Cologne.

Because of recurring engine problems, operations by the Manchesters were very sporadic. It was not until the night of 12/13 March 1941 that No. 207 Squadron was active again, sending four aircraft to Hamburg. On the following night the squadron lost its first Manchester to enemy action, when an aircraft captained by Flying Officer Hugh Matthews was shot down by an intruder as it took off from Waddington for another attack on Hamburg. Only one crew member survived.

No. 207 Squadron was now joined by a second Manchester squadron, No. 97, which began re-equipping in March 1941. Both squadrons joined in Bomber Command’s offensive, which at this time was directed principally against German warships and their ports, but continued problems with the Vulture engines meant that the Manchesters were frequently grounded. It was a relatively common occurrence for a Manchester crew to complete a sortie to Germany or the French Atlantic ports without trouble, only to have their aircraft’s engines overheat uncontrollably as they returned to base, often with disastrous results.

In April 1941, when all forty Manchesters then in service were grounded to have engine bearings replaced, it was discovered that repeated overheating of the Vultures was causing the oil to lose its viscosity in one-fifth of the expected time. This accounted for the frequent engine seizures that were being experienced. Morale, understandably, was not at its best in the Manchester squadrons.

More Manchester squadrons continued to form, however. No. 61 Squadron received its first aircraft in July 1941; these were Mk 1As, featuring larger fins, which cured the poor handling of earlier aircraft. Four other squadrons, Nos 83, 106, 50 and 49 also received Manchesters by the end of the year. By that time, the trouble-plagued bombers were regular participants in operations over Germany with bomb loads of up to 8000 lb, but more often than not they were restricted to attacking German naval vessels in the Channel ports with armour-piercing bombs.

The last operational Manchester sortie, a raid by a single aircraft on Bremen, was flown on the night of 25/26 June 1942. Of the 1200 Manchesters that had originally been ordered from Avro, only 200 had been delivered before the type was withdrawn.

While production of the Manchester was in progress, one airframe, BT308, was designated a ‘four-engined Manchester’ and fitted with four Rolls-Royce Merlin XX engines. It first flew on 9 January 1941 with triple fins and without ventral or dorsal turrets, and was the prototype of an aircraft that would become a legend: the Avro Lancaster.

The feelings of a typical aircrew member about the Avro Manchester were expressed by Flight Lieutenant Bob Jones, a former wireless operator air gunner who had flown in Handley Page Hampdens and then Manchesters.

The only time I started to get really frightened was when we converted on to Manchesters. During my very first trip in a Manchester the port engine burst into flames and we scraped in by the skin of our teeth. On another occasion we took a Manchester from Waddington to Boscombe Down to have some equipment fitted, and were marooned there for a week because the engines wouldn’t start. Soon after that I went sick and was in hospital for three months. I’m convinced to this day that it saved my life; I lost a hell of a lot of good mates in Manchesters. They were bastards.

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